It's a sheltered publicly accessible space in an urban environment. Station is being built using cut-and-cover so the entire length of the station (platform and headhouse) will be excavated anyways, not sure if that makes a differernce. For the New York subway comparison, it has smaller...

Around 1 1/2 the width of Queen St, which considering it being the only station building, and has to fit in elevators and escalators, is not big.

If it's wide enough, they can also easily do cut-and-cover east from Victoria Park. The section between Don Mills and Victoria Park will definitely be tunnel bored.

There is also a GO train station right next to Markville with planned all-day service.

Trees cannot be planted anywhere on the keyhole site. The station headhouse only takes up the south end. From the factum:

Scarborough Centre is no longer in "Scarborough Centre"?

It will not improve the Line 1-OL connection. There aren't a lot of options to connect two intersecting centre platforms.

The long ramps/stairs are there because pedestrain cannot cross the tracks at some stations. There would be long ramps regardless of low floor or high floor vehicles. If it's at-grade, they aren't much longer than the usual ramps. 39 Avenue station: https://goo.gl/maps/JZ6S9Vnp2jkXmeqPA

At the end it wasn't really about the trees. Trees were the pawns. The whole thing snowballed to include dissatisfaction about the station design, Metrolinx' lack of transparency, and the government in general. Some are new, some have existed before this fiasco. They are valid reasons, but...

However, that makes more sense as a non-fare paid zone connection. I guess they can add another row of fare gates between that and whatever underground level of the west keyhole (Simcoe St. entrance) it's connected to.

The station diagram on Steve Munro's blog provides much needed insight. I can't call the design perfect, but it's doing the best with cards dealt. The design avoids the mess we have at Eglinton/Yonge by steering clear of the existing station box as much as possible. Line 1 - OL direct...

On closer look, it looks to be a variant of a turbo roundabout, so probably not quite vanilla. The centre lane (the lane closest to the roundabout centre?) splits, but there is no need to switch over to the new centre lane unless someone is trying to do a 270 degrees turn back to Queen.

From Hespeler northbound: The right lane goes through the roundabout and onto Hespeler, hence the straight arrow. The lane markings guide you to the Hespeler exit. You cannot/should not use it to get to Beaverdale as that would be a lane change within the roundabout. The left lane is for...

In that case, the right lane has to drop off, or else those coming off express will have to do three lane changes to exit Kennedy.

It would not be just travel time savings if it was put underground (or elevated). The entire line would be grade-separated with no in-median/street-running, so theoretically, they could redesign it to run high-floor metro trains.

^ This would actually be a good place to have a radiant snow melting system. (for safety, environment, and comfort)

Such a shame the eastern part of crosstown wasn't elevated - especially when they will run a parallel local bus service anyways.

Where can they put the second exit for Dundas? Yonge/Gould ?

Similar to how Sudbury has Science North and Dynamic Earth (which Science North operates).

If Metrolinx really wants to assign numbers to all rail transit lines in the GTHA, then this could be line 10 (and line 8 for Hamilton's King St. LRT). The numbers aren't assigned to any other lines (yet), might as well use them.